Image copyrightles observateurs france24Image caption
The Goma protest took place outside the offices of the National Intelligence Agency

At least 11 people have been arrested in the Democratic Republic of Congo's eastern city of Goma for protesting against the detention of pro-democracy activists, officials have said.

Two Belgians who were at the protest were assaulted by the security forces, according to the Belgian embassy.

DR Congo's government has accused the detained activists, who include Senegalese and Burkinabe nationals, of plotting an insurgency with US backing.

The US has denied the allegation.

It said the pro-democracy event on Sunday in the capital, Kinshasa, was non-partisan.

Concern about stability in resource-rich DR Congo has been mounting ahead of presidential elections due next year.

At least 40 people were killed during protests in January after the opposition raised concern that President Joseph Kabila planned to delay the polls in order to cling to power - a charge the government denied.

'Historian beaten up'

The head of the UN mission in DR Congo, Martin Kobler, said he was concerned about the arrests and the Belgian and US embassies were holding meetings with Congolese officials to discuss the issue.

The Goma protest took place outside the offices of the National Intelligence Agency.

The assaulted Belgians included a historian and a journalist, a spokesperson for the Belgian embassy said.

Security officials said 11 demonstrators - all Congolese - had been arrested, while protest organisers put the number at 12.

On Sunday, US diplomat Kevin Sturr was arrested by DR Congo's police after he attended a press conference hosted by pro-democracy activists.

He was later released, but at least 18 activists are still in police custody.

They include those who played a key role in organising protests that led to the overthrow of Burkina Faso's long-serving ruler Blaise Compaore last year, and against efforts by then-Senegalese President Abdoulaye Wade to extend his 12-year term in 2012 in defiance of the constitution.

The US embassy said it had partly sponsored the meeting of Congolese and other activists so that they could exchange ideas and young people could "express their views about issues of concern to them".